Monday, 27 May 2013

Rates of dementia higher in Indigenous Australians

Indigenous Australians have much poorer health outcomes and higher rates of some illnesses than non-Indigenous Australians. Estimates from the Australian Bureau of Statistics (ABS) show than an Indigenous male born in 2005-2007 was likely to live to 67.2 years, about 11.5 years less than a non-Indigenous male (who could expect to live to 78.7 years). An Indigenous female born in 2005-2007 was likely to live to 72.9 years, which is almost 10 years less than a non-Indigenous woman (82.6 years). They also have higher infant mortality rates, at between 5-13 for every 1,000 births (depending on the state), compared to 4 in every 1,000 for the total population.

ABS research also shows that Indigenous Australians on average also have higher rates of cardiovascular disease, cancer, diabetes, kidney disease and asthma.

A ground-breaking recent study has also found that they are more likely to suffer from dementia.

A three-year study titled Koori Growing Old Well Well was conducted between 2009 and 2012 across five urban and regional Indigenous communities in New South Wales. It involved 336 participants aged over 60 years. Preliminary results revealed that at 21 percent the prevalence of dementia is three times the rate of non-Indigenous Australians. It also found that there is an earlier age of onset amongst Aboriginal Australians, with almost three quarters of participants with dementia being aged between 60 and 70 years, compared to other Australians where the majority of people with dementia are aged over 70 years.

The poorer overall health of Aboriginal Australians plays a role in their higher rates of dementia. Risk factors for some forms of dementia include high blood pressure, obesity, smoking and diabetes.

The lead researcher, Professor Tony Broe reported "Aboriginal people in urban areas have a high incidence of many of the risk factors that have been linked to dementia in studies around the world".

Some issues with research in this field are that some Indigenous people are reluctant to share their health issues and do not want to accept that their loved ones have dementia.

These results have prompted doctors to call for appropriate services tailored specifically for the Indigenous community. Professor Broe says the findings will be used to develop education and services for older Indigenous people with dementia and for their families.

Tuesday, 21 May 2013

Could previous researchers have been wrong about the role of amyloid in Alzheimer's disease?

Amyloid proteins in the brain have long been implicated as the culprit behind Alzheimer's disease. Amyloid are insoluble protein aggregates that arise from inappropriately folded proteins and polypeptides. These form tangles or plaques. They have been associated in the pathology of more than 20 serious neurodegenerative disorders, including Alzheimer's disease. They’re thought to disrupt the seamless workings of the neurons responsible for memory and movement.
Recent studies in the US and in Australia, have however found that amyloid may not be as destructive as previously thought.

Two recent US studies have found that amyloid proteins may in fact play a protective rather than a destructive role in the brain. The studies run by Professor Lawrence Steinman of Stanford University found that treating mice with multiple sclerosis (MS) with amyloid proteins reduced brain inflammation and reversed MS-related paralysis.

A second study extended the finding to show that small portions of several notorious amyloid-forming proteins (including tau and prion proteins) can also alleviate symptoms in mice with the condition — despite the fact that the fragments can and do form the long tendrils, or fibrils, previously thought harmful to nerve health. This supported previous research showing that Alzeimer's disease is much worse in animals born without the genes that produce amyloid.

He reported, "we were so fixated on the idea that amyloid is bad for the brain that if one goes back and looks at the old literature and the new literature, one finds there's a lot of publications where people have ignored these kinds of experiments in humans where, for instance, lower levels of amyloid are associated with earlier dementia".

In another recent Australian study run by Dr Bryce Vissel of the Garvan Institute of Medical Research, researchers have found that the amyloid plaques that are characteristic of Alzheimer's disease appear much later in the disease than previously thought, and after the development of cognitive symptoms. This indicates that neurodegenerative processes such as memory loss and executive dysfunction occur independently of amyloid plaques.

Instead it is proposed that inflammation in the brain is the leading cause of brain damage and neurodegeneration in Alzheimer's disease. Lawrence suggested that amyloid proteins may soak up harmful molecules that are responsible for inflammation.

The studies suggest that anti-amyloid therapies may not be the best way to manage the disease, and that therapies focusing on reducing inflammation may be more beneficial.

Friday, 17 May 2013

The importance of wearing helmets

Australia is one of the few countries in the world with mandatory helmet laws for motorcyclists and bicycle riders. They were introduced in 1991 in New South Wales and have been the subject of controversy since. A recent study provides evidence supporting the importance of wearing helmets in reducing the risk and severity of head injury, particularly for bicycle riders.

Dr Michael Dinh from the University of Sydney and colleagues studied 348 adult patients admitted to hospitals following bicycle and motorcycle accidents in Sydney for one year between 2008-2009.

They found that cyclists who didn't wear helmets were almost 6 times more likely to suffer a head injury than those wearing helmets, and more than 5 times more likely to suffer a severe head injury. The benefits for motorcyclists were not as marked but still significant, with those without helmets 2 times more likely to suffer a head injury and 3.5 more likely to suffer a severe head injury compared to those without helmets.

Head injuries are rated on a scale from mild to extremely severe, based on a ranges of factors including level of consciousness following the incident and length of coma.

These outcomes also have implications for hospital care. The study found that patients who suffered severe head injuries from not wearing a helmet cost hospitals 3 times as much in treatment. For those who suffered a severe head injury, median hospital costs for non-helmeted patients were $72,000 while for those with helmets the figure was $24,000.

Older riders were more likely to wear helmets than younger riders. The average age of helmet wearing cyclists was 41, compared to 35 for non-helmet wearers, and for motorcyclists the average ages were 31 for those wearing helmets and 25 for those who did not.

The study was published in the Medical Journal of Australia. It supports previous research on the subject. In 2011 Dr Jake Oliver and colleagues from the University of New South Wales and the Sax Institute studied the number of head injuries before and after the mandatory helmet laws came into effect. They found that head injuries fell by up to 29%.

There are clear benefits from helmet wearing that clearly outweigh concerns about mandatory helmet laws reducing the number of cyclists. Studies such as those by Dr Dinh and Dr Oliver have also prompted debate about the usefulness of mandatory helmet laws in the US. More information can be found here.